On rf-magnetoresistance and flux flow resistivity of NbTi

✍ Scribed by A. Philipp; K. Luders; K.D. Kramer

• Book ID: 103051655
• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 465 KB
• Volume: 18
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(78)90043-7

✦ Synopsis

The temperature and magnetic field dependences of the surface impedance of Nb5OWt/o Ti were investigated with a TEml-mode cavity operated at a frequency of 9.67 GHz. The results with the cavity cooled down in the earth's magnetic field show good agreement with the BCS-behaviour of the surface resistance in the Meissner state when a reduced gap, A(O)/kB T c of 1.97, and a mean free path of O.5 nm are assumed. Measurements in external magnetic fields up to 3 T were used to obtain the flux flow resistivity (FFR) of Nb Ti. The FFR obtained in this way shows a marked deviation from the phenomenological straight line behaviour pf/p n = B/Hc 2, which has been found all low-and medium-K superconductors. This indicates that the high K of Nb Ti leads to reduced flux flow losses at lower magnetic fields in qualitative agreement with calculations by Hu and Thompson for gapless high-K superconductors. Investigations of the temperature dependence of the ffr resulted in a resistance minimum being deeper and occurring at higher temperatures than those which have been reported for all other materials investigated to date.